title: [Is there a shift in the epidemiology of hepatitis A in Mexican children?].
abstract: BACKGROUND
  Twenty years ago, prevalence of Hepatitis A in Mexican children was 90%.
  
  
  OBJECTIVE
  To describe a shift in the prevalence of Hepatitis A virus (HAV) infection and to demonstrate an increment in the age at the first contact with HAV, in a sample of Mexican children.
  
  
  METHODS
  Reports of antiviral serologic studies collected from 1991 to 2005 from patients attending a pediatric hospital, were reviewed, and those with IgM anti-HAV positive in serum were selected. Age at the moment of acute infection was analyzed. Additionally, a serological survey searching IgG anti-HAV was made in a group of HAV unvaccinated children.
  
  
  RESULTS
  From 1708 determinations of IgM, 221 were positive (13%). According to the year of report, five groups were constituted. Mean age by group was: 1991-1993 of 6.4 years, 1994-1996 of 8.0, 1997-1999 of 8.4, 2000-2002 of 8.0 and from 2003-2005 of 10.1 years. In a cohort of 259 unvaccinated children (mean of age 8.59 years), IgG antibodies were detected in 51%.
  
  
  CONCLUSIONS
  In the infantile population studied a Hepatitis A epidemiology shift is suggested.
authors.affiliation: Servicio de Infectología, Hospital de Pediatría, Centro Médico Nacional Siglo XXI IMSS, DF México.
authors.forename: Ireri
authors.initials: I
authors.lastname: García-Juárez
authors.forename: Fortino
authors.initials: F
authors.lastname: Solórzano Santos
authors.forename: María Teresa
authors.initials: MT
authors.lastname: Alvarez-y-Muñoz
authors.forename: José Guillermo
authors.initials: JG
authors.lastname: Vázquez-Rosales
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D006506:Hepatitis A / Q000453:epidemiology*; D006801:Humans; D007223:Infant; D008297:Male; D008800:Mexico / Q000453:epidemiology; D015995:Prevalence; D012189:Retrospective Studies; D013997:Time Factors